Closed tank application for bubbler Level Measurement Principle

If the bubbler system is to be applied to measure level in a closed tank, some pressure-regulating scheme must be provided for the gas space in the tank.

Otherwise, the gas bubbling through the liquid will pressurize the gas space to a point where bubbler supply pressure cannot overcome the static pressure it acts against. The result would be no bubble flow and, therefore, inaccurate measurement signal.

Also, as in the case of a closed tank inferential level measurement system, the low-pressure side of the level transmitter has to be connected to the gas space in order to compensate for the effect of gas pressure.